# Kilogram and Density

Topics: Kilogram, Gold, Mass Pages: 5 (1249 words) Published: March 27, 2013
CHAPTER 1
1.

List the seven SI base quantities, units, and symbols.

TIME Second (s)
2.

Give the correct SI derived units of the following quantities. Density Speed Acceleration Force Pressure kg/m3

Energy

3.

Convert the following: μm (Ans. 1.22)

a. 1.22 x 10-9 km = b. 6.523 x 10-4 nm = c. 2.5x 10-9 nm3 = d. 30.5 cm/s = e. 9.6 ng/mm2 = 4.

Mm (Ans. 6.523 x 10-19) mm3 (Ans. 2.5 x 10-27) km/h (Ans. 1.09 x 106) kg/m2 (Ans. 9.6 x 10-6)

Perform the following calculations and report each answer with the correct number of significant figures and units. b. 2.457 m x 1.2 m x 2.45 m d. 3.6050 cm x (24.10 cm - 23.10 cm)

a. 3.45 m – 3.4 m c. (50.214 g – 49.93 g) x 1.224 cm / 55.22 cm3 e. 4.0 x 102 cm – 3 cm f.

2.7612g  2.7601g 
2.20cm 3

g 26.167m  83m
5.100m

h.

12.64 cm – 48 mm + 0.246 m (answer in meters) 7.87 g/m2 (16.1 m – 8.44 m)

i.

Ans. a) 0.1 m; b) 7.2 m3; c) 6.3 x 10-3 g/cm2; d) 3.61 cm2; e) 4.0 x 102 cm; f) 5.0 x 10-4 g/cm3; g) 21.4 g/m3; h) 0.324 m ; i) 1.03 g/cm3 5.

The element beryllium is considered toxic at a concentration of 3.0 x 10-12 g/cm3. What is this concentration in ng/m3? (Ans. 3.0 x 103)

6.

The average density of the earth is 5.52 g/cm 3. What is its density in: a) μg/mm3? (Ans. 5.52 x 103) b) lb/ft3? (1 lb = 453.6 g; 1 in = 2.54 cm) (Ans. 345)

7.

Diamond has a density of 3.513 g/cm3. The mass of diamonds is often measured in “carats” where 1 carat = 200 mg. What is the volume (in cm 3) of a 2.5 carat diamond? (Ans. 0.14) The density of a liquid alcohol is 0.79 g/cm 3. A tank measuring 3.2 m x 0.0020 km x 4.1 mm is filled with the alcohol. What is the mass of the contents in kg? (Ans. 21) The density of gold is 19.3 g/ cm 3. A 3.4 mg sample of gold is hammered into a square foil that is 8.6 × 10−6 cm thick. What is the length of a side of the square, in cm? (Ans. 4.5) A 14-karat gold ring contains 58.3% gold and weighs 12.41 g. If gold sells for \$276.00/ounce, what is the value of the gold in the ring? (1 oz = 28.35 g) (Ans. \$70.4) A packing material has a density of 12.8 kg/m 3. How many lbs of this material are needed to fill a 2.00 ft3 box? (1lb = 454 g; 1in = 2.54 cm) (Ans. 1.60 lb)

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12.

A jogger runs at an average speed of 6.5 mi/h. (1 mile = 1.609 km; 1 in = 2.54 cm) a) How fast is she running in m/s? (Ans. 2.91 m/s) b) How many kilometers does she run in 98 min? (Ans. 17 km) c) How long should it take her to cover 12 km? (Ans. 1.1 h) d) If she starts a run at 11:15 am, what time is it after she covers 4.75 x 10 4 ft? (Ans 12:38pm)

13.

Manganese makes up 1.3 x 10-4 percent by mass of the elements found in a normal healthy body. How many grams of manganese would be found in the body of person weighing 183 lbs? (2.2 lb = 1.0 kg) (Ans. 0.11 g) If 5.00 lbs of mercury cost \$175 and mercury has a density of 13.6 g/cm3, what is the cost of 2.00 L of mercury? (1 lb = 454 g) (Ans. \$ 2.10 x 103) If a raindrop weighs 65 mg on average and 5.1 x 10 5 raindrops fall on a lawn every minute. What mass (in kg) of rain falls on a lawn in 2.5 h? (Ans. 5.0 x 103 kg) A concentrated sulfuric acid solution has a density of 1.84 g/cm3 and contains is 95.7% H2SO4 by mass. (Note: density of a solution means mass of solution divided by volume of solution.) a) How many grams of pure H 2SO4 are contained in 1.00 gallon of this solution? 3.785 L) (Ans. 6.66 x 103) (1 gallon =

14.

15.

16.

b) How many mm3 of this solution contain 100.0 mg of pure H2SO4? ( Ans 56.8 mm3) 17.

A gold alloy has a density of 12.4 g/ml and contains 75.0% gold by mass. Calculate the volume of this alloy that can be made from 255 g of pure gold. (Ans. 27.4 mL)

18.

Whole milk contains 8.0 % butterfat by mass. If 5.0 g butterfat supplies 15 calories, how many calories are contained in 1.45 gallons of whole milk ( density of milk = 0.8 g/ml; 1 gallon = 3.785 L) (Ans. 1.1 x 103 cal) Earth’s oceans have an average depth of 3.800 x 10 3 m, a...